Shears



w '1 un I ll i Dec. 25, 1945. T ERDICH 2,391,598

SHEAR Filed July 15, 1944 I NVEN TOR.

Y Theodore Serd Patented Dec. 25, 1945 UNITED STATES PATENT OFFICE SHEARS I Theodore Serdich, Gary, Ind. Application July 15, 1944, Serial No. 545,083

3 Claims. or. 30 2ss) This invention relates to shears for cutting sheet metal and the like, and it consists in the constructions, arrangements and combinations herein described and claimed.

It is the cardinal object of the invention to provide a pair of shears adapted to cutting of sheet metal along curved or irregular lines without liability of catching of the severed metal in or against the cutting blades or other parts of the shears.

It is also an object of the invention to provide hand shears in which the cutting blades are pivoted in a manner so as to obtain a great leverage, thus reducing the effort of cutting sheet metal to a minimum.

A further important object of the invention is to provide shears in which the cutting blades are removably mounted so that the blades may be sharpened when required.

Additional objects, advantages and features of invention will be apparent from the following description and accompanying drawing, wherein Figure 1 is a perspective view of shears constructed in accordance with the invention.

Figure 2 is a rear elevation thereof.

Figure 3 is a bottom plan view thereof.

Figure 4 is a perspective view of one of the cutting blades detached.

Figure5 is a similar view of the other cutting blade.

Figure 6 is a side elevation of a modified form of shears.

Figure 7 is a bottom plan view thereof.

Figure 8 is a cross section on the line 8-8 of Figure 6.

Attention is first invited to Figures 1 to 5 wherein a shearing device I is illustrated, consisting of a base ll of elongated form of substantial thickness at the rear end l2, the upper surface tapering downwardly toward the forward end l3 to permit the ready insertion of the end beneath a plate to be severed. The bottom face I4 is smooth so as to rest upon a supporting surface.

The edge l of the body H is formed at right angles to the base [4 and medially of the length thereof, a rabbeted portion I6 is formed, within which there is detachably mounted a cutting blade 11, the outer face of which is convex, this edge cooperating with a concave blade presently to be described.

The body H is formed at the rear portion l2 with a lateral extension I8 projecting beyond the edge l5 and includes an integral upright wall l9 extended longitudinally of the base but stopping short of the forward end l3. The wall I9 has a pair of ears at the forward end for pivotally mounting an operating lever 2|. The lever 2| is slotted as at 22, adjacent the inner side wall thereof inwardly of the pivot 23 of the handle.

I: A short link 24 is pivotally mounted within the slot 22, the opposite end being disposed within a slot 25 formed in the upper side of a blade mounting 26. The blade mounting block 26 is in the form of a rectangular block, one vertical side face being smoothly finishedso as to lie flush against the adjacent face of the wall l9. Adjacent the rear end of the mounting block 26 an opening 21 is formed extending transversely therethrough aligned with an opening 28 in the wall l9, a pintle i inserted through the openings swingably supporting the mounting block 26. The other vertical side face of the mounting block 26 is undercut at its lower edge forming a, rabbet 30 within which a cutting blade 3| is detachably mounted. The cutting blade Si is formed with a concave front face 32 complemental to the convex face 33 of the blade ii. The wall l9 and blade mounting 26 are so proportioned and located that the cutting edges of the blades I1 and 3| will contact one,

another to effect a shearing of material disposed therebetween.

As may be seen in Figure 2, the base I l is formed with an arcuate slot 34 intermediate the height of the base H, the slot extending from one rear corner of the base, the wall 35 of the slot merging with the convex face 33 of the blade l1. By this construction, it will be apparent that as the metal is being out along an arcuate line, one portion of the metal will pass freely along the upwardly tapering top surface of the base, while the other portion of the metal will pass outwardly through slot 34.

It will be seen that when the operating lever 2| is raised upwardly, the link 24 will draw upon the forward end of the mounting block 26 swingable about the pivot pin 29, so as to raise the blade 3 l, permitting insertion of the material to be cut. Downward pressure on the handle 2| will cause corresponding movement of the block 26 and associated cutting blade, the latter being presented to the metal so as to effect a draw out.

The cutting blades 11 and 3| are detachably mounted by means of machine screws 36, by which means the blades may be removed for sharpening or replaced by new blades.

In Figures 6, 7 and 8 a modified form of shears is shown, in which a fixed handle and a movable handle are employed.

In this instance, the base 31 is formed with an elongated supporting foot 38, the forward end of which is tapered upon the lower and upper surfaces, as at 39, enabling sheet material to be cut to more readily move into position between the cutting blades, as will be understood as the description continues. As may be seen from Figure 8, the foot 38 is formed integrally at its upper end with an angularly disposed plate 40, the latter terminating in a vertical wall 4| which' extends parallel to the foot 38 but in spaced relation thereto, the distance of the cutting blades to be described. 7

The forward -end of the wall 4| terminates in a pair of ears 42 between which a movable handle 43 is pivotally mounted by means of a pintle 44. A fixed handle 45 is formed as an integral part of the wall 4| extending in a plane coincident with the movable handle 43. The movable handle 43 is of a length less than the handle 45 so as to present the thumb loop 46 approximately intermediate the length of the finger loop 41 of the handle 45. By this arrangement a very comfortable operating grip i provided, permitting ready movement of the handle 43 while the handle 45 may be manipulated to advance the shears forwardly, as the cutting operation progresses.

A cutting blade 48 is pivotally mounted upon the wall 4i as at 49, the opposite end being slotted along the upper edge to receive a link 50 pivotally mounted by means of a pin The underside of the handle 43 is also slotted at its forward end to receive the other end of the link 50, the link being pivoted within the slot by means of a pin 52. By this mounting of the blade, it will be seen that the blade will be raised and lowered upon actuation of the handle 43. The cutting edge 53 is formed integrally with the blade and is of concave contour complemental to a convex cuttin blade 54 detachably mounted upon the inner face of the foot 38. The inner face of the foot 38 has a curvature coinciding with that of the convex blade 54 extending to the rear of the foot permitting passage and guidance of severed material.

While I have shown and described preferred forms of the device, this is by way of illustration only, and I consider as my own all such modifications in construction as fairly fall within the scope of the appended claims.

I claim: 1. A tool for cutting sheet material in an arcuate path comprising a base member constructed and adapted to pass beneath a, sheet to be out, said base having an arcuate shaped cutting blade thereon, a blade mounting pivotally carried by said base and having a blade in opposed relation to the first named blade and having a curvature complemental to said first named blade, and handle means for moving the blade mounting and associated blade toward and away from said arcute shaped cutting blade, said base being formed with a curved slot the vertical wall of which is a continuation of the cutting edge of said lower blade.

2. A tool for cutting sheet material in an arcuate path comprisin a base member constructed and adapted to pass beneath a sheet to be out, said base having an arcuate shaped cutting blade upon one edge thereof, said base having an upright wall laterally spaced from the base,

the forward end of the wall having ears thereon, an operating lever pivotally mounted between said ears, a blade mounting pivotally mounted upon an upper rear portion of the upright wall, said blade mounting having an arcuate shaped blade fixed'in opposed relation to said first named cutting blade and complemental thereto, a link member-pivotally connected to a forward end of the blade mounting and said operating lever, and said base member being formed with a curved slot, the vertical wall of which is a continuation of the cutting edge of the lower blade.

3. A tool for cutting sheet material in an areuate path comprisin a base member constructed and adapted to pass beneath a sheet to be cut, said base having an arcuate shaped cutting blade upon one edge thereof, said base having a laterally offset upright wall extending forwardly and parallel to the base and having ears thereon, said base further having a rearward shank terminating in a loop for the reception of the fingers of an operator, an arcuate shaped cutting blade pivotally mounted at an upper rear portion of the upright wall, an operating lever pivotally mounted between said ears, a link pivotally connected between a forward upper portion of said last named cutting blade and said operating lever,

said operating lever terminating in a thumb loop in advance of the loop on the shank, and said base member being formed with a curved slot the vertical wall of which is a continuation of the cuttin edge of said lower blade. j

THEODORE SERDICH. 

